This application is a 371 of PCT/JP00/01607 filed Mar. 16, 2000.
The present invention relates to an agent for alleviating side effects caused by use of an anti-tumor agent.
Most drugs employed in chemotherapy to treat cancers act upon proliferating cells to arrest the cell cycle and prevent proliferation of the cells, to thereby terminate proliferation of the cancer tissue or reduce the cancer tissue. However, such drugs also act upon the mucosal cells of the digestive tract, where cell proliferation is active. Therefore, it is well-known that proliferation of mucosal cells in the digestive tract is also prevented, thereby causing shrinkage of mucosal villi; reducing the resistance of the digestive tract against external stimulation such as food; causing inflammatory conditions; and inducing disorders of the digestive tract such as diarrhea and inhibition of nutrient absorption.
When cancer is treated through the administration of an anti-tumor agent, side effects such as nausea, vomiting, diarrhea, and loss of body weight make these drugs very difficult for patients to tolerate. Thus, it is not uncommon in clinical practice that drug administration must be intermitted. In order to alleviate such side effects, compounds have been employed in combination.
For example, a dithiobis (2,2-dimethylpropionamide) derivative is employed with a fluoropyrimidine anti-tumoragent (Japanese Patent Application Laid-Open (kokal) No. 10-158163); a dithiobis(carboxylic acid) derivative is employed with a fluoropyrimidine anti-tumor agent (Japanese Patent Application Laid-Open (kokai) No.10-158159); conagenin is employed with cancer chemotherapeutic agents such as antimetabolites, alkylating agents, and plant-derived compounds (Japanese Patent Application Laid-Open (kokai) No. 8-165236); a pyrimidine nucleocide phosphorylase inhibitor is employed with 5xe2x80x2-deoxy-5-fluorouridine (Japanese Patent Application Laid-Open (kokai) No. 5-213761); and oxonic acid is employed with a fluoropyrimidine anti-tumor agent (Japanese Patent Application Laid-Open (kokai) No. 5-78249). Of these, only oxonic acid is actually employed in clinic. In a clinical setting, administration of Hange Shashin Tou is discussed so as to prevent delayed diarrhea caused by irinotecan hydrochloride (CPT-11).
However, the capacity of the aforementioned means to alleviate side effects is less than satisfactory.
Thus, an object of the present invention is to provide a drug which can considerably reduce side effects, e.g., such as nausea, vomiting, diarrhea, loss of body weight, and anorexia, caused by administering an anti-tumor agent to an organism, thereby alleviating the side effects suffered by patients and allowing cancer treatment by the use of an anti-tumor agent to continue, which treatment must be intermitted by these side effects.
In view of the foregoing, the present inventors have carried out extensive studies from various points of view on 5-chloro-6-(2-iminopyrrolidin-1-yl)methyl-2,4(1H,3H)-pyrimidi nedione or a pharmaceutically acceptable salt thereof, and have found that these compounds can effectively alleviate digestive-tract-related side effects such as nausea, vomiting, diarrhea, loss of body weight, and anorexia, which side effects are caused by an anti-tumor agent. The present invention has been accomplished on the basis of this finding.
Accordingly, the present invention provides an agent for alleviating side effects caused by use of an anti-tumor agent, which comprises, as an active ingredient, 5-chloro-6-(2-iminopyrrolidin-1-yl)methyl-2,4(1H,3H)-pyrimidinedione represented by formula (1): 
and a pharmaceutically acceptable salt thereof.
The present invention also provides use of the aforementioned compound represented by formula (1) or a pharmaceutically acceptable salt thereof for producing an agent for alleviating side effects caused by use of an anti-tumor agent.
In addition, the present invention also provides a method for alleviating side effects caused by an anti-tumor agent, which comprises administering the aforementioned compound represented by formula (1) or a pharmaceutically acceptable salt thereof.